The present invention relates to an electronic control system for a vehicle and a method for determining at least one driver-independent intervention in a vehicle system. The invention particularly relates to a method for avoiding accidents and injuries by the integration of the active and passive safety means and the active driving dynamics control in an electronic control system of a vehicle.
In the past, passive safety systems for avoiding any injuries induced by accidents have mainly been developed separately and independently of active safety systems for avoiding accidents.
The first major improvements of passive safety in the middle of the sixties implying the safety passenger cell, the three-point seat belt, up to the later development of the deformation zone, did not yet represent a break-through in the improvement of active safety. It was only with the wide spreading of ABS at the beginning of the eighties that the foundation for active electronic safety systems was formed.
Since then, electronically controlled systems such as ESP driving dynamics control systems, ACC, seat-belt tensioning devices, and airbags are being employed for active and passive safety.
The entire potential of the individual systems is, however, fully utilized only if the systems are interconnected in a network and data about the driving condition, the vehicle's ambience and the driver himself is available to all subsystems. The idea of a network has been realized in a first step in the project Reduced Stopping Distance (‘Reduced Stopping Distance RSD, title ‘30 m car’, Continental group of companies, December 2000) in the field of active safety systems. A specific brake tire serves as the basis for shortening the stopping distance, which, due to its bionomical structure, will not only increase its wheel contact area when a brake force is applied but also ensure a homogeneous distribution of the forces in the tire contact area. This fact increases the maximum possible deceleration to roughly 1.3 g with optimal road conditions. To be able to transmit this high brake torque onto the road in the case of an emergency braking, intervention in the shock absorbers is necessary to dampen the pitch oscillation induced by the impact of braking in the direction of aperiodicity. This provides the ABS with better control conditions and renders it more efficient. The average transmissible brake torque is increased by the minimized wheel load fluctuations. In particular when a wheel encounters slip at the beginning of the emergency braking operation, the network connection between the adjustable dampers and the ABS control allows adjusting the optimum of wheel slip with a higher rate of accuracy.
The entire stopping maneuver is furthermore shortened by the quicker pressure increase that is possible due to the use of an electrohydraulic brake system (EHB). In this arrangement, the application of the brake pedal is analyzed, and the pressure out of a pressure accumulator is fed into the brake system assisted by a brake assist system (BA). This allows reducing the threshold time and, thus, shortening the travel that is covered from the point of time of the first brake pedal contact until the full development of the braking power.
The network connection has been extended in the following improvement by integrating ambience data. A 77 GHz radar sensor or a LIDAR distance sensor included in the Adaptive Cruise Control (ACC) supplies the distance and relative speed of the vehicles in front of one's own vehicle. The comfort-oriented ACC control uses this data to permit the driver relaxed and non-tiring driving relieved from routine tasks (distance-keeping).
An activated ACC system, however, also enhances safety for an inattentive driver. The ACC system recognizes a dangerous situation and initiates an independent braking maneuver at a critical distance and a relative speed until the allowed limit of 2 to 3 m/s2. If this deceleration is insufficient to avoid a collision, the driver is warned by a signal and requested to perform a braking maneuver.
This provision will shorten the travel any inattentive driver covers until he has recognized the risk and starts to reposition his foot to depress the brake pedal.
With the consequent linking of distance sensor and brake system, this shortening of the reaction travel can also be used when the ACC system is deactivated. When the driver takes over to perform the braking maneuver in this dangerous situation, the extended brake assist system (BA+) will support the driver in the further brake pressure buildup.
DE 198 06 687 A1 discloses a method for preventing a collision of a vehicle with an object positioned in front of the vehicle. In this arrangement, the distance and the relative speed between the vehicle and obstacle and the speed and the acceleration or deceleration of the vehicle are detected, and collision indications or braking operations are initiated depending thereon. As this occurs, a braking operation shall only be initiated when the sensed distance is shorter than two calculated distances. One calculated distance represents a minimum distance which allows avoiding a collision at a maximum deceleration, while the other distance is meant to allow directing the vehicle past the object.
Further, WO 03/006289 discloses a method for the automatic activation of a deceleration of a vehicle for preventing a collision with another object, wherein depending on radar or Lidar signals or video signals, objects in the range of the vehicle's course are detected and motional quantities of the vehicle are sensed. A risk potential shall be determined depending on the object detected and the motional quantities. According to this risk potential, the means of deceleration shall be operated in at least three conditions. In addition, it is envisaged to diminish the consequences of an imminent collision with another object by activating passive or active restraint systems.